(0) Obligation:

JBC Problem based on JBC Program:
/**
* Example taken from "A Term Rewriting Approach to the Automated Termination
* Analysis of Imperative Programs" (http://www.cs.unm.edu/~spf/papers/2009-02.pdf)
* and converted to Java.
*/

public class PastaB2 {
public static void main(String[] args) {
Random.args = args;
int x = Random.random();
int y = Random.random();

while (x > y) {
x--;
y++;
}
}
}


public class Random {
static String[] args;
static int index = 0;

public static int random() {
String string = args[index];
index++;
return string.length();
}
}


(1) JBCToGraph (SOUND transformation)

Constructed TerminationGraph.

(2) Obligation:

Termination Graph based on JBC Program:
PastaB2.main([Ljava/lang/String;)V: Graph of 179 nodes with 1 SCC.


(3) TerminationGraphToSCCProof (SOUND transformation)

Splitted TerminationGraph to 1 SCCs.

(4) Obligation:

SCC of termination graph based on JBC Program.
SCC contains nodes from the following methods: PastaB2.main([Ljava/lang/String;)V
SCC calls the following helper methods:
Performed SCC analyses:
  • Used field analysis yielded the following read fields:
  • Marker field analysis yielded the following relations that could be markers:

(5) SCCToIntTRSProof (SOUND transformation)

Transformed FIGraph SCCs to intTRSs. Log:

Generated rules. Obtained 8 IRules

P rules:
f661_0_main_Load(EOS, i120, i121, i120) → f664_0_main_LE(EOS, i120, i121, i120, i121)
f664_0_main_LE(EOS, i120, i121, i120, i121) → f667_0_main_LE(EOS, i120, i121, i120, i121)
f667_0_main_LE(EOS, i120, i121, i120, i121) → f671_0_main_Inc(EOS, i120, i121) | >(i120, i121)
f671_0_main_Inc(EOS, i120, i121) → f674_0_main_Inc(EOS, +(i120, -1), i121)
f674_0_main_Inc(EOS, i128, i121) → f677_0_main_JMP(EOS, i128, +(i121, 1)) | >=(i121, 0)
f677_0_main_JMP(EOS, i128, i129) → f703_0_main_Load(EOS, i128, i129)
f703_0_main_Load(EOS, i128, i129) → f658_0_main_Load(EOS, i128, i129)
f658_0_main_Load(EOS, i120, i121) → f661_0_main_Load(EOS, i120, i121, i120)

Combined rules. Obtained 1 IRules

P rules:
f661_0_main_Load(EOS, x0, x1, x0) → f661_0_main_Load(EOS, -(x0, 1), +(x1, 1), -(x0, 1)) | &&(<(x1, x0), >(+(x1, 1), 0))

Filtered ground terms:


f661_0_main_Load(x1, x2, x3, x4) → f661_0_main_Load(x2, x3, x4)
Cond_f661_0_main_Load(x1, x2, x3, x4, x5) → Cond_f661_0_main_Load(x1, x3, x4, x5)

Filtered duplicate terms:


f661_0_main_Load(x1, x2, x3) → f661_0_main_Load(x2, x3)
Cond_f661_0_main_Load(x1, x2, x3, x4) → Cond_f661_0_main_Load(x1, x3, x4)

Prepared 1 rules for path length conversion:

P rules:
f661_0_main_Load(x1, x0) → f661_0_main_Load(+(x1, 1), -(x0, 1)) | &&(<(x1, x0), >(+(x1, 1), 0))

Finished conversion. Obtained 1 rules.

P rules:
f661_0_main_Load(x0, x1) → f661_0_main_Load(+(x0, 1), -(x1, 1)) | &&(>(x0, -1), >(x1, x0))

(6) Obligation:

Rules:
f661_0_main_Load(x0, x1) → f661_0_main_Load(+(x0, 1), -(x1, 1)) | &&(>(x0, -1), >(x1, x0))

(7) PolynomialOrderProcessor (EQUIVALENT transformation)

Found the following polynomial interpretation:


[f661_0_main_Load(x3, x5)] = -x3 + x5

Therefore the following rule(s) have been dropped:


f661_0_main_Load(x0, x1) → f661_0_main_Load(+(x0, 1), -(x1, 1)) | &&(>(x0, -1), >(x1, x0))

(8) YES